OpenAI investors are pressing the company’s board to reverse its decision to fire Sam Altman as chief executive officer and remove him as a director, according to people with knowledge of the matter.

Some of the investors including Thrive Global are also in talks with Microsoft Corp., the largest shareholder of OpenAI, said the people, who asked not to be identified because the overtures are private.

Altman is open to returning to the company, one of the people said. In one scenario under consideration, members of the current OpenAI board would step down as soon as this weekend, according to multiple with knowledge of the situation. However, the situation is still fluid and no decisions have been made, the people said.

Microsoft CEO Satya Nadella has been in touch with Altman and pledged to support him in whatever steps he takes next, the people said. Nadella was blindsided by the board’s decision, according to people familiar with the situation.

Representatives of San Francisco-based OpenAI and Redmond, Washington-based Microsoft declined to comment. Thrive declined to comment.

The OpenAI board has been subjected to intense criticism over its decision to remove Altman, which came as a surprise to both investors and to Altman himself.

Several people, including co-founder Greg Brockman, have departed from the company in protest. The resignations are likely to continue, the people said.

If Altman were to return, he would ask for changes in the way the company is governed, some of the people said.

If he does not return, Altman has been considering launching a new venture, possibly with former staffers of OpenAI, according to people familiar with the matter.

--With assistance from Rachel Metz.

(Updates with context starting in the second paragraph.)

Author: Emily Chang, Ashlee Vance and Ed Ludlow